APLICATION OF REMOTE SENSING AND GIS FOR COASTAL ECOSYSTEM MANAGEMENT

 

APLICATION OF REMOTE SENSING AND GIS FOR COASTAL ECOSYSTEM MANAGEMENT

CHAPTER I

INTRODUCTION

A.  REMOTE SENSING

Remote sensing technology in recent years has proved to be of great importance in acquiring data for effective resources management and hence could also be applied to coastal environment monitoring and management (Ramachandran, 1993, Ramachandran et.al., 1997, 1998). Further, the application of GIS (Geographical Information System) in analyzing the trends and estimating the changes that have occurred in different themes helps in management decision making process.

Remote sensing is the measurement of object properties on earth’s surface usinng data acquired from aircraft and satellities. It attempts to measure something at a distance, rather than in situ, and for this research’s purposes, displays those measurements over a two-dimensional spatial grid, i.e. images. Remote sensing systems, particularly those deployed on satellites, provide a repetitive and consistent view of earth facilitating the ability to monitor the earth system and the effects of human activities on Earth. There are many electromagnetic (EM) band-lenght ranges Earth’s atmosphere absorbs. The EM band ranges transmittable through Earth’s atmosphere are sometimes referred to as atmospheric windows.

When electromagnetic radiation falls upon a surface, some of its energy is absorbed, some is transmitted through the surface, and the rest is reflected. Surfaces also naturally emit radiation, mostly in the form of heat. It is that reflected and emitted radiation which is recorded either on the photographic film or digital sensor. Since the intensity and wavelengths of this radiation are a function of the surface in question, each surface is described as processing a characteristic ʺSpectral Signatureʺ. If an instrument can identify and distinguish between different spectral signatures, then it will be possible to map the extent of surfaces using remote sensing. Satellite remote sensing is widely used as a tool in many parts of the world for the management of the resources and activities within the continental shelf containing reefs, islands, mangroves, shoals and nutrient rich waters associated with major estuaries.

B.  Geographical Information Systems

A Geographical Information System (GIS) is a system of hardware, software and procedures to facilitate the management, manipulation, analysis, modeling, representation and display of geo‐referenced data to solve complex problems regarding planning and management of resources. Functions of GIS include data entry, data display, data management, information retrieval and analysis. The applications of GIS include mapping locations, quantities and densities, finding distances and mapping and monitoring change.

Function of an Information system is to improve one’s ability to make decisions. An Information system is a chain of operations starting from planning the observation and collection of data, to store and analysis of the data, to the use of the derived information in some decision making process. A GIS is an information system that is designed to work with data referenced to spatial or geographic coordinates. GIS is both a database system with specific capabilities for spatially referenced data, as well as a set of operation for working with data. There are three basic types of GIS applications which might also represent stages of development of a single GIS application.

CHAPTER II

Application of Remote Sensing and GIS in Coastal Ecosystem Management

Based on remote sensing a variety of data pertaining to the coastal zone like, identification of plant community, biomass estimation, shoreline changes, delineation of coastal landforms and tidal boundary, qualitative estimation of suspended sediment concentration, chlorophyll mapping, bathymetry of shallow waters, etc. can be collected and all these data will help in effective coastal ecosystem management.

The latest Indian satellites IRS – 1C, 1D, P4 and P6 with their improved spatial resolution (PAN – 5.8 m, LISS III – 23.6 m, LISS IV – 5.8 m, WiFS – 188 m and AWiFS – 56 m), extended spectral range (inclusion of middle infrared band in LISS – III) and increased repetivity (5 days for WiFS data) have opened up new applications in coastal zone. Preliminary analysis of IRS – 1C, 1D data indicates that coral reef zonation, identification of tree and shrub mangroves, mudflats, beach, dune vegetation, saline areas, etc as well as better understanding of suspended sediment patterns are now possible. The PAN data combined with the LISS – III and LISS ‐ IV data are extremely useful in providing detailed spatial information about reclamation, construction activity and ecologically sensitive areas, which are vital for the coastal zone regulatory activities. The information available from merged PAN and LISS III, IV data about coral reef zonation, especially for atolls, patch reef and coral pinnacles, is valuable for coral reef conservation plans. The distinction between tree and shrub mangroves in FCC (middle infrared, infrared and red bands) of LISS III provides vital information on biodiversity studies (Ramachandran et. al., 2000a). The high temporal resolution provided by the WiFS data is found to be a major improvement in studying the behavior of suspended sediments in the coastal waters, which would help in understanding the movement of sediments and pollutants (Nayak et.al., 1996).

CHAPTER III

CONCLUSION

Coastal ecosystems are of great importance and of immense value to mankind in the present and in the future. They are being degraded at an alarming rate by various preventable activities including that of human interference. The coastal ecosystems are to be monitored periodically for better management plans. The satellite based sensors provide valuable information useful in assessment, monitoring and management of coastal ecosystems. Optical remote sensing data is very useful for mapping the coral reef, mangrove and lagoon ecosystems. The information, which is thus derived, can be very useful in the coastal ecosystem management, which is greatly required for the sustainable use, development, and protection of the coastal and marine areas and resources. Thus remote sensing and GIS technologies are widely used today in coastal ecosystem management.

References

Bastin. J. (1988). Measuring areas of coral reefs using satellite imagery, Symposium on Remote Sensing of the Coastal Zone, Gold Coast Queensland. p vii.1.1‐vii.1.9.

Hussin. Y.A, Mahfud, M. and Zuhair Michael Weir (1999). Monitoring Mangrove Forests using Remote Sensing and GIS. GIS development proceedings, ACRS.

IGBP (1994). Land‐Ocean Interactions in the Coastal Zone, Report No. 33. p74.

IOM report (2001). No Impact Zone Studies in Pulicat Lake. Submitted to Dept. of Ocean Development, Govt. of India.

Ramachandran. S. (1993). Coastal Zone Information System – Pilot project for Rameswaram area. Report submitted to Department of Ocean Development. Govt. of India, 40 pp.